A hydrodynamic torque converter is a device used to amplify and transmit torque within step-type or single-input clutch automatic transmissions, replacing the conventional plate clutch or clutch pack often found in standard or manual transmissions. Conventional torque converters are contained within a separate housing that is bolted to the engine flexplate and positioned between the engine and the transmission, and therefore the torque converter housing turns or rotates at engine speed whenever the engine is running. A torque converter is comprised of a number of key structural members that cooperate to enable the engine crankshaft to continue rotating while the vehicle is stationary, for example while idling at a stop light or in heavy traffic. The key structural members include a turbine, i.e. the driven member of the torque converter, which is drivingly connected to the transmission gearbox, a stationary stator for redirecting the flow of fluid within the torque converter as the fluid exits the turbine, and a centrifugal pump and cover assembly, i.e. the driving member of the torque converter which is directly connected to the torque converter housing.
In contrast to a single-input clutch automatic transmission employing a hydrodynamic torque converter, a dual-input clutch transmission, also referred to as a DCT transmission, employs odd and even gears which are disposed on separate, coaxial rotatable input shafts. This divided gear arrangement allows each of two separate input clutches, typically wet or fluid lubricated friction clutch packs, to be dedicated to a respective subset of gears, thereby providing a smoother gear shifting event, which in turn may increase fuel efficiency while reducing shift shock. However, in spite of its enhanced shift performance capabilities, DCT transmissions generally require a greater amount of axial packaging space due to the greater relative size of the dual-input clutch than is required by a single-input clutch using a conventional torque converter.